I see mapping a drive to `/' as `proper' configuration. (i.e. If Wine is meant to integrate apps to the Unix environment, it shold be able to see the full Unix environment.)
Ah, there is where my opinion diverges the most from most of the people here (and why I advocate a lot for the Desktop option).
I do *NOT* want to have my Windows and my Linux stuff to mix together. So I always use Dekstop mode and I have clearly delimited Windows drives for Wine.
Lionel (who wonders if he's the only one in this case :-) )